Carbocationic polymerizations in general and living carbocationic polymerizations in particular are of great scientific and practical importance for the creation of useful materials. Living carbocationic polymerizations (LC+Ps) proceed in the absence of chain transfer and termination (collectively termed chain breaking) and lead to well-defined designed useful polymers. LC+Ps lead to predetermined degrees of polymerization (molecular weights), narrow molecular weight distributions, desirable end-groups, and sequential (block, graft, etc.) polymers. The mechanism of LC+Ps is well known in the art. (See, Designed Polymers by Carbocationic Macromolecular Engineering, by J. P. Kennedy and B. Ivan, Hanser pub, 1992, the disclosure of which is incorporated herein by reference in its entirety). The chemistry of initiation of cationic polymerizations is discussed in detail in Carbocationic Polymerization, by J. P. Kennedy and E Marechal, Wiley, 1982, pp. 81-116, and specifically that of LC+P, pp 9-31, the disclosure of which is incorporated herein by reference in its entirety.
The initiator that is used world-wide for the production of well-defined telechelic PISS (by LC+P of isobutylene) by academic and industrial investigators, is 5-tert-butyl-1,3-bis(1-chloro-1-methylethyl)benzene (abbreviated herein as HDCCl, for hindered dicumyl chloride):
